Lactoferrin concentrations in bovine milk during involution of the mammary glands, with different bacteriological findings

Lactoferrin is an iron-binding glycoprotein of the transferrin family, present in high concentrations in secretions from the mammary glands during the involution period, and has antimicrobial ability. To determine lactoferrin concentrations in bovine milk with different bacteriological findings, 151 quarter milk samples were collected on a dairy farm of the Holstein-Friesian breed in Vojvodina, Republic of Serbia. Classical microbiological methods were used for bacteria isolation, and ELISA analysis was used for lactoferrin concentration quantification. The most common isolated bacteria in bovine milk samples were Corynebacterium spp. (32.45%) and coagulase-negative staphylococci (4.64%) with lactoferrin concentrations of 6.0497 +/- 1.6774 mg/mL and 5.2961 +/- 1.3633 mg/mL, respectively. The lowest mean value of lactoferrin concentration was observed in uninfected quarters and quarters infected with environmental pathogens, while the highest concentration of lactoferrin was in udder quarters infected with Streptococcus agalactiae. One in four milk samples where Staphylococcus aureus was isolated had much lower lactoferrin concentrations (1.1736 mg/mL) than the other three samples (6.2089 +/- 0.5016 mg/mL), which requires further research.